A DJ play mixes different musics and reproduces the musics called non-stop remixes for a long period of time without interruption. The DJ play drastically develops by adopting the “scratch” technique which appeared in 1990s and uses the slide rheostat or resistor called the fader to create a rhythm by chopping up a music. The advent of this technique enables DJ devices such as a record player, CD, DJ mixer, etc. to be used like musical instruments. As a result, a new music genre was established and has become popular to the young generation.
When DJ devices are used like musical instruments in a way completely different from that for conventional stringed or keyboard instruments, phonographic records or CDs are only presently available sound sources. Accordingly, the power of expression is greatly restricted.
In order to enhance the power of expression, it may be possible to use a computer or a keyboard instrument. However, it is difficult to demand many practices and high proficiency from users in order to master the computer or the keyboard instrument anew in the field of DJ plays where many users create musics with acute sensitivity and based on their intuition. This makes it difficult for users to easily create music suitable for the DJ play.